Daily use of chlorine dioxide effectively treats halitosis: A meta-analysis of randomised controlled trials

Objectives: We aimed to conduct a systematic review on published data in order to investigate the efficacy of mouthwash products containing chlorine dioxide in halitosis. Study design: Systematic review and meta-analysis Methods: Our search was conducted on 14th October 2021. We searched the following electronic databases: MEDLINE, Embase, Scopus, Web of Science, and CENTRAL. We analysed data on adults with halitosis, included only randomised controlled trials and excluded in vitro and animal studies. The interventional groups used chlorine dioxide, and the comparator groups used a placebo or other mouthwash. Our primary outcomes were changes in organoleptic test scores (OLS) and Volatile Sulfur Compound (VSC) levels from baseline to the last available follow-up. Results: We found 325 articles in databases. After the selection process, ten articles were eligible for qualitative synthesis, and 7 RCTs with 234 patients were involved in the meta-analysis. Our findings showed a significant improvement in the parameters of the chlorine dioxide group compared to the placebo group in OLS one-day data (mean difference (MD): -0.82; 95% confidence intervals (95% CIs): [-1.04 –-0.6]; heterogeneity: I2 = 0%, p = 0.67); and one-week OLS data (MD: -0.24; 95% CIs: [-0.41 –-0.07]; I2 = 0%, p = 0.52); and also changes in H2S one-day data (standardised mean difference (SMD): -1.81; 95% CIs: [-2.52 –-1.10]); I2 = 73.4%, p = 0.02). Conclusion: Our data indicate that chlorine dioxide mouthwash may be a good supportive therapy in oral halitosis without known side effects.